Silk nano-discs: A natural material for cancer therapy

Abstract

The article demonstrates the crystalline silk nano-discs (CSNs), with well-controlled morphology, which upon magnetization, yields magnetic crystalline silk nano-discs, making both prominent alternatives for replacing metal templates such as gold, silver, and so on in therapeutics and implants. The isolated β-sheet-rich discotic CSNs have ~50 nm diameter, high crystallinity (> 90%), and are insoluble but provide good dispersibility and stability in aqueous solutions. The melt blending-cum-electrospinning of functionalized CSN with poly(lactic acid) results in biocompatible nanofiber-based scaffolds having in vitro cell cytocompatibility with improved cell adhesion and proliferation. The assessment of release behavior of curcumin, a naturally occurring anticancer drug, shows sustained release over 25 days exhibiting effective cytotoxicity against human cervical cancer cells. Further, combined effect of curcumin and hyperthermia reduced the cell growth by ~63%. Alignment of CSN-derived magnetic nanoparticles due to effective fiber drawing process during electrospinning could improve cytocompatibility against BHK-21 cells, and therefore efficacy for cancer therapy.

Keywords: cytotoxicity; electrospinning; magnetic nanoparticles; silk; β-sheet.